The Noisy Ocean

Susan Parks discusses the impact of sound pollution on marine mammals

Image: Penn State

The Noisy Ocean

Kelsey Bradbury, Research Unplugged intern

November 16, 2010

The songs of whales echoed through the atrium of the Penn State Downtown Theatre last Wednesday as Susan Parks addressed an audience of more than 60 people. Parks led a dynamic discussion on the effects of noise pollution on whale and dolphin communication.

"My friends always ask me if I study the mystical 'land whale' of Pennsylvania," she joked at the outset, "but most of my work takes place in other parts of the country."

Parks' research is focused on the right whale, a type of baleen whale. "The largest baleen whale, the blue whale, can be up to 100 feet. It's the largest animal ever to live on the planet," said Parks. "Baleen whales communicate in the low frequency range, so this is a population that is likely to be more impacted by noise in the environment."

"Whales have limited visibility to obtain resources that are widely distributed. Visibility in the summer can be limited to 2-3 meters," she explained. "A right whale can't actually see its own flipper. Acoustically, though, sound propagates much more efficiently under water. It's about 4.5 times faster underwater."

"If you think of the way you go through your daily life noticing things visually," Parks added, "whales have a different perspective: they notice things acoustically first. They can use vision, but they probably use it as backup the way we use sound."

Parks acknowledged that, compared to other threats to marine mammals such as hunting and injuries related to fishing nets, sound pollution is responsible for relatively few deaths each year. But she is worried about the future. "I'm studying acoustic effects because of the impending potential for background noise to keep going up to the point where it's going to break down communication and have really serious long-term effects," she explained. "Hopefully it's something we can actually get a handle on before it becomes a major problem. This is one of the things that we know humans are introducing to the environment. Human activities are generating noise and it is changing the marine environment."

Currently, whales are still able to modify their communication to compensate for noise pollution. Parks shared the results of a recent study: "You see almost no whales calling at high intensity in low noise; so, it seems they are calling louder in increased noise. Right whales have some compensation mechanisms, but we don't know when that breaks down."

Parks noted a hopeful trend of some agencies taking steps towards decreasing acoustic pollution. "The International Maritime Organization—which oversees all commercial shipping—is actually being really proactive with this and is pushing quieting technology to make large ships quieter," she told the crowd. "Quieter ships are more cost efficient, but they also help the environment. And that's great."

Join Research Unplugged on Wednesday, November 17, for our final conversation of the fall semester: "Chopin and the Romantic Imagination: A Lecture/Recital Commemorating Chopin's Bicentennial Year," a performance event featuring Penn State music professor, Eric McKee, and student pianist, Mi-Jin Lee.

Bioacoustics researcher Susan Parks discusses the challenges that right whales face in trying to communicate with each other in an increasingly noisy ocean, at the November 17 Research Unplugged at Penn State's Downtown Theatre.